Case Studies

Issue

A continuous surface lignite mine was facing issues with boom lowering hydraulic cylinders of compact type bucket-wheel excavator. Only a few years into operation, the cylinders were experiencing continuous leakage and malfunction (piston seal by-pass).

The large diameter cylinders were exposed to heavy payload, shock load, pressure peaks, and deflection by long stroke and angle position.

Compact lignite bucket-wheel excavator.

Recommendation

The Chesterton team developed a seal system that was installed during a planned overhaul.

The sealing solution included Chesterton® 5K Wiper, 10K Rod Seal, 10K Piston Seals, and replaceable 19K Bearing Bands. A combination of innovative sealing materials was used:

• AWC800 proprietary polymer: Best-in class sealing technology with high wear and abrasion and extrusion resistance.
• AWC660: A high loading capacity, engineered plastic with built-in lubricants that prevent metal-to-metal scoring and prolong equipment life.

Bucket-wheel boom lowering cylinders in operation.

Improved cylinder performance and reliability

• The end-user was extremely satisfied with the performance.
• Extending the hours of operation between maintenance intervals and increasing the overall asset life.
• Environmental concerns were eliminated by leak-free operation of the rod seal system.
• The high-performance piston seal system reduced the possibility of cylinder malfunction.

Boom lowering cylinders in repair shop.